var pi = 3.14159265358979324;
var a = 6378245.0;
var ee = 0.00669342162296594323;
var x_pi = 3.14159265358979324 * 3000.0 / 180.0;
        
function CheckXYGpsToGoogle(wgLon, wgLat)
{
    var googleXY = new Array();
    googleXY.push({"lat":wgLat,"lng":wgLon});
    try
    {
        if (outOfChinaGoogle(wgLat, wgLon)) {  
            googleXY[0].lat = wgLat;  
            googleXY[0].lng = wgLon;  
            return googleXY;  
        }  
        var dLat = transformLatGoogle(wgLon - 105.0, wgLat - 35.0);  
        var dLon = transformLonGoogle(wgLon - 105.0, wgLat - 35.0);  
        var radLat = wgLat / 180.0 * pi;  
        var magic = Math.sin(radLat);  
        magic = 1 - ee * magic * magic;  
        var sqrtMagic = Math.sqrt(magic);  
        dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);  
        dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);  
        googleXY[0].lat = wgLat + dLat;  
        googleXY[0].lng = wgLon + dLon; 
    }
    catch(e)
    {
        
    }
    return googleXY;
}

function CheckXYGoogleToGps(wgLon, wgLat)
{
    var googleXY = new Array();
    googleXY.push({"lat":wgLat,"lng":wgLon});
    try
    {
        if (outOfChinaGoogle(wgLat, wgLon)) {  
            googleXY[0].lat = wgLat;  
            googleXY[0].lng = wgLon;  
            return googleXY;  
        }  
        return GCJToGPSGoogle(googleXY);
    }
    catch(e)
    {
        
    }
    return googleXY;
}

function outOfChinaGoogle(lat, lon) {  
    if (lon < 72.004 || lon > 137.8347)  
        return true;  
    if (lat < 0.8293 || lat > 55.8271)  
        return true;  
    return false;  
}  

function transformLatGoogle(x, y) {  
    var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));  
    ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;  
    ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;  
    ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;  
    return ret;  
}  
  
function transformLonGoogle(x, y) {  
    var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));  
    ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;  
    ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;  
    ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;  
    return ret;  
}  

function GCJToGPSGoogle(googleXY)
{
    var wgLon = googleXY[0].lng;
    var wgLat = googleXY[0].lat;
    if (outOfChinaGoogle(wgLat, wgLon))
    {
        return;
    }
    var gps = transformGoogle(googleXY);
    var lontitude = wgLon * 2 - gps[0].lng;
    var latitude = wgLat * 2 - gps[0].lat;
    googleXY[0].lng = lontitude;
    googleXY[0].lat = latitude;
    return googleXY;
}

function transformGoogle(googleXY)
{
    var wgLon = googleXY[0].lng;
    var wgLat = googleXY[0].lat;
    var d = new Array();
    d.push({"lat":googleXY[0].lat,"lng":googleXY[0].lng});
    var mgLat;
    var mgLon;
    if (outOfChinaGoogle(wgLat, wgLon))
    {
        mgLat = wgLat;
        mgLon = wgLon;
        return d;
    }
    var dLat = transformLatGoogle(wgLon - 105.0, wgLat - 35.0);
    var dLon = transformLonGoogle(wgLon - 105.0, wgLat - 35.0);
    var radLat = wgLat / 180.0 * pi;
    var magic = Math.sin(radLat);
    magic = 1 - ee * magic * magic;
    var sqrtMagic = Math.sqrt(magic);
    dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
    dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
    mgLat = wgLat + dLat;
    mgLon = wgLon + dLon;
    d[0].lng = mgLon;
    d[0].lat = mgLat;
    return d;
}
